This 2.3 volt button cell is used in Casio watches. This lithium battery is rechargeable with solar energy and is a high quality battery that provides a long service life. Lithium batteries, rechargeable in the sun 2.3 volts, works in a variety of temperatures from -20°C to 60°C. It has a service life of 10 years. **Note: All batteries must be operated with anti-static plastic tweezers, non-powder gloves or latex gloves. Static electricity and impurities from the hands can damage the cell. Due to the low voltage of these cells, you do not need to use a battery or voltage meters to test them.